sorroundings
When we consider a chemical reaction, we need to take into account both the system and the surroundings. The system includes the components involved in the chemical reaction itself. These will often take place in a flask, a beaker, a test tube, or some other container. The surroundings include everything that is not part of the system. When potassium reacts with water, part of the heat energy generated in the reaction is released into the surroundings. The boundary between system and surroundings is arbitrary, and it is generally chosen in a way that makes observations and calculations easier.